Abstract:We take the data of local earthquakes in Jiangsu-Anhui section and adjacent area of Tan-Lu fault zone in recent 50 years as data samples. Based on the quantitative analysis of the minimum complete magnitude(MC) of this area, and the systematically derived principle of the maximum likelihood method for the calculation of b-value, this paper focuses on the study of the G-R relationship in the area, especially the evolution characteristics of the temporal and spatial distribution of the b-value. According to the indication of the b-value, the correlation between the b-value and earthquakes with ML≥5 in the area, and the distribution of the crustal tectonic stress indicated by the b-value, are analyzed. According to the characteristics of the temporal distribution of b-value, the period of occurrence of moderate and strong earthquakes obviously coincides with the period of medium and short-term decline of b-value, and the correlation rate is over 80%. The spatial distribution of b-value indicates that the crustal stress of the whole north Jiangsu basin, the south of the basin and the southern margin of Hefei basin, is relatively high; it is consistent with the distribution of UHP metamorphic belt in the region. Combined with relevant geological data, we infer that the region is in the stage of earthquake preparation.
YU Teng,WANG Xin,LI Mingfeng et al. Research on the b-Value Space-Time Characteristics in Jiangsu-Anhui Section and Adjacent Area of Tan-Lu Fault Zone[J]. jgg, 2021, 41(2): 173-179.